CN108988711B - A kind of motor control method of the electronic bridge plug delivery tool in oil field - Google Patents
A kind of motor control method of the electronic bridge plug delivery tool in oil field Download PDFInfo
- Publication number
- CN108988711B CN108988711B CN201810799787.0A CN201810799787A CN108988711B CN 108988711 B CN108988711 B CN 108988711B CN 201810799787 A CN201810799787 A CN 201810799787A CN 108988711 B CN108988711 B CN 108988711B
- Authority
- CN
- China
- Prior art keywords
- voltage
- bridge plug
- delivery tool
- oil field
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P7/00—Arrangements for regulating or controlling the speed or torque of electric DC motors
- H02P7/06—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current
- H02P7/18—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power
- H02P7/24—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices
- H02P7/28—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices
- H02P7/285—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices controlling armature supply only
- H02P7/292—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual dc dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices controlling armature supply only using static converters, e.g. AC to DC
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Electric Motors In General (AREA)
- Control Of Direct Current Motors (AREA)
Abstract
The invention discloses a kind of oil field motor control methods of electronic bridge plug delivery tool, comprising: Step 1: establishing the Controlling model of remote power-feeding motor；Step 2: before work of going into the well, the resistance value of measure traverse line, and according to the parameter of the resistance value Correction and Control model；Step 3: the electric current in the course of work in real-time measurement circuit, and gradient is adjusted according to the voltage that the electric current and current changing rate obtain power supply；Step 4: calculating control voltage, it is output to power-supply controller of electric, to control the output voltage of power supply；Wherein, during the work time, when the amplitude that the electric current in circuit reduces is more than threshold value, it is judged as that bridge plug is installed, prompts gug, control process terminates.The motor control method of the electronic bridge plug delivery tool in oil field provided by the invention, using the electric current in the circuit of real-time measurement as feedback signal, the output voltage of adjustment programmable DC regulated power supply in real time guarantees that the stabilization of the motor operating voltage of bridge plug delivery tool is moved in the electricity consumption of underground oil field.
Description
Technical field
The invention belongs to the control technology field of remote power-feeding motor, in particular to a kind of oil field is launched with electronic bridge plug
The motor control method of tool.
Background technique
The bridge plug of oil extraction in oil field needs to launch the underground for being installed to a few km depths, is moved before delivery tool using gunpowder
Power, complicated for operation, accident rate is high.The features such as electronic bridge plug delivery tool is due to safe and reliable, process control, is such tool
Developing direction.
Electronic bridge plug delivery tool is using dc motor as power device, it is therefore desirable to use dedicated cable --- hold lotus
Detection cable (meeting professional standard SY/T6600-2004) is powered and is controlled, and it is more that the structure of this cable is that steel wire is wrapped in
Core (below 7 cores) conducting wire, this cable can not only bear the lifting power of underground equipment, can also transmit a variety of underground equipments
Power supply and signal.Because of the limitation of cable size, sectional area of wire can only be 0.24~1.01mm2, common WB7P-10.8 seven
The conductor resistance of core cable is 36 Ω/km, since the depth of oil well is all in 3km or more, so two electricity of motor power supply line
The internal resistance of cable at least also has 200 Ω or more.Since the resistance of cable is already close to the internal resistance for being even more than motor, electricity
The power in source will have quite a few consumption on cable, and the resistance of cable makes the accurate control and power performance of downhole electrical motor
At very big influence.
Further, since the depth disparity of oil well is very big, the cable of different length will use when electrical installation is gone into the well.And electricity
Cable often has damage, repairs Shi Douhui and cuts out damaged part, the length of every cable is caused all to be different.Dc motor
Operating current can change with the variation of workload, and circuital current change when will cause on conducting wire pressure drop change
Change, is equivalent to the voltage allocation proportion for changing conductor resistance and electrical equipment, the work of motor on electronic bridge plug delivery tool
Voltage cannot remain in rated condition.Due to above, fixed indemnifying measure can not solve these dynamic problems, it is necessary to
According to the working condition of bridge plug, motor operating voltage shakiness is solved the problems, such as using dynamic control method.
Summary of the invention
It is an object of the present invention to provide a kind of oil field motor control methods of electronic bridge plug delivery tool, for electricity
The motor circuit and work characteristics of dynamic bridge plug delivery tool are calculated using the electric current in the circuit of real-time measurement as feedback signal
The voltage distribution condition of circuit out adjusts the output voltage of programmable DC regulated power supply, to offset the electricity on cable in real time
Crushing loses (pressure drop), guarantees that the stabilization of the motor operating voltage of bridge plug delivery tool is moved in the electricity consumption of underground oil field.
Another object of the present invention is to overcome the efficiency that cannot be considered in terms of voltage adjustment and the technical issues of stability,
Voltage adjustment process is rationally divided into multiple adjustment periods, can be under the premise of guaranteeing motor stabilizing work, it quickly will be electric
Pressure is adjusted to target value.
Technical solution provided by the invention are as follows:
A kind of motor control method of the electronic bridge plug delivery tool in oil field, comprising:
Step 1: measuring the resistance value of cable before going into the well, the voltage Controlling model of power supply is determined；
Step 2: the electric current in the course of work in real-time measurement circuit, and obtained according to the electric current and current changing rate
The voltage of power supply adjusts gradient；
Step 3: control voltage is calculated, to control the output voltage of power supply；
U(n)=U(n-1)+ΔU；
In formula, U(n)To control voltage value, U(n-1)For current output voltage value, Δ U is that voltage adjusts gradient；
Wherein, during the work time, when the amplitude that the electric current in circuit reduces is more than threshold value, it is judged as that bridge plug installs
At.
Preferably, the calculation method of the voltage adjustment gradient includes:
Step 1 determines target voltage values；
Step 2 calculates target voltage increment；
Step 3, calculating reach the control periodicity of the target voltage increment；
Step 4 calculates voltage adjustment gradient.
Preferably, in the step 3, the control periodicity are as follows:
In formula, CNMax is maximum control periodicity；CNMin is minimum control periodicity；ΔIffFor the change of filtered electric current
Rate；ΔImax、ΔIminRespectively maximum current increment and minimum current increment.
Preferably, in the step 1, target voltage values are as follows:
Uobj=Uload_C+RIff；
Wherein, Uload_CFor Rated motor voltage；R is cable resistance, IffFor filtered current value.
Preferably, in the step 2, target voltage increment are as follows:
DU=Uobj-U(n-1)；
In formula, UobjFor target voltage values, U(n-1)For current output voltage value.
Preferably, in the step 4, the voltage adjusts gradient are as follows:
In formula, dU is target voltage increment, and CycNum is control periodicity.
Preferably, interference signal, filtered current value are inhibited using single order low-pass digital filter are as follows:
In formula,Respectively (n-1)th and the filtered current value of n-th；For n-th sampling
Current value；A is filter factor.
Preferably, the threshold value is 0.5A/s.
The beneficial effects of the present invention are:
(1) present invention is directed to the motor circuit and work characteristics of electronic bridge plug delivery tool, using circuital current as feedback
Signal extrapolates the voltage distribution condition of circuit, the especially electric power loss of cable, and using model analysis, adjustment can be compiled
The output voltage of journey D.C. regulated power supply guarantees downhole electrical motor operating voltage to offset the loss of voltage (pressure drop) on cable
Stabilization.
(2) present invention uses dynamic process control strategy, according to the telecommunication information of programmable DC regulated power supply,
The working condition (output voltage and electric current) of solution circuit determines line build-out measure by analytical calculation, real-time control power supply
Output parameter, when efficiently solving cable change in resistance and motor load change, the operating voltage Preserving problems of downhole electrical motor.
(3) voltage adjustment process is rationally divided into multiple adjustment periods by the present invention, can guarantee motor stabilizing work
Under the premise of, voltage is quickly adjusted to target value, has not only improved the regulated efficiency of voltage, but also avoids that motor is caused to impact.
Detailed description of the invention
Fig. 1 is the electric machine control system structural schematic diagram of electronic bridge plug delivery tool of the present invention.
Fig. 2 is of the present invention for measuring the circuit diagram of cable resistance.
Fig. 3 is voltage adaptive control strategy schematic diagram of the present invention.
Fig. 4 is the change curve of the voltage and current in a bridge plug installation process of the present invention.
Specific embodiment
Present invention will be described in further detail below with reference to the accompanying drawings, to enable those skilled in the art referring to specification text
Word can be implemented accordingly.
The present invention provides a kind of oil field motor control methods of electronic bridge plug delivery tool.As shown in Figure 1, of the invention
The electric machine control system of the electronic bridge plug delivery tool used are as follows: 220V AC power source passes through programmable DC regulated power supply 110
DC voltage is exported, is transported to the electricity of downhole electric bridge plug delivery tool by the dedicated charge bearing detecting cable 120 in oil field later
Machine 130；Control the output voltage that computer 140 controls D.C. regulated power supply 110 by serial communication.
Oil field provided by the invention is as follows with the motor control method of electronic bridge plug delivery tool:
Firstly, establishing the Controlling model of the remote power-feeding motor based on circuit current feedback.Since direct current generator passes through
Voltage controls revolving speed, so motor control model are as follows:
Umotor=Usource-IRwire；
UmotorI η=Pload；
Wherein, UmotorFor the operating voltage of motor, I is the operating current of motor, UsourceFor supply voltage, RwireFor electricity
Cable resistance, η are electric efficiency, PloadFor bearing power, change in real time.According to the motor control model, need in cable electricity
Press IRwireSupply voltage is adjusted when variation, in real time to guarantee motor operating voltage UmotorStabilization.
Later, the resistance value R of cable is measuredwire.In the present embodiment, by control circuit as shown in Figure 2, to measure
The resistance value of cable.Using the motor parallel of switch K and bridge plug delivery tool, after equipment completes system connection, prepare to go into the well
Before, by lower switch K, controls computer command power supply and export a voltage, the voltage and current data then transmitted according to communication port,
Calculate the resistance R of cablewire.Pressure drop IR on cablewireOnly change with electric current, and the operating voltage of motor needs to keep permanent
Fixed (stablizing in voltage rating), to obtain the Controlling model of determining supply voltage.
The motor control method of the electronic bridge plug delivery tool in oil field provided by the invention, using ADAPTIVE CONTROL,
Design voltage gradient adaptive controller, when circuital current changes, control computer 110 can obtain in real time from communication port
The information of curent change in the circuit of feedback, and supply voltage is adjusted according to the electric current of feedback in time, guarantee electric equipment under ground
The response speed and control stability of (load motor).
As shown in figure 3, the ADAPTIVE CONTROL of supply voltage, includes the following steps:
Step 1, target voltage computing module are according to load motor voltage rating Uload_C(it is motor characteristic parameter, constant
Value) and circuit in Real-time Feedback electric current Iff, cable resistance R.Target voltage values are determined according to formula (1):
Uobj=Uload_C+RIff (1)
Later, the target voltage values U that will be calculatedobjIt is transferred to target voltage incremental computations module.Wherein, anti-in real time
Supply current IffFor filtered electric current.
In the present embodiment, interference signal is inhibited using single order low-pass digital filter, samples the electric current in the circuit of acquisition
Signal is input to filter, through filtered electric current IffIt is separately input to target voltage computing module and derivative module.Wherein, it filters
The Controlling model of wave device are as follows:
Wherein,Respectively (n-1)th and the filtered current value of n-th；For n-th sampling
Current value；A is filter factor.
Step 2, target voltage incremental computations module are according to the target voltage values U receivedobjAnd current output voltage value
U(n-1)Target voltage increment dU value is obtained by subtracter operation, calculation method is shown in formula (3):
DU=Uobj-U(n-1) (3)
Later, target voltage increment dU value is exported to control period computing module and voltage gradient computing module.
Step 3, control periodicity computing module calculate target voltage increment and several control periods are needed to reach, and will calculate
Control periodicity out is output to control voltage gradient computing module.
Wherein, the calculation method of the control periodicity are as follows:
In formula, CNMax is maximum control periodicity；CNMin is minimum control periodicity；ΔIffFor the change of filtered electric current
Rate；ΔImax、ΔIminRespectively maximum current increment and minimum current increment.Wherein, filtered current changing rate Δ Iff
For filtered electric current IffIt is obtained by derivative module operation.Wherein, the maximum control week under current goal voltage increment demand
Issue CNMax are as follows:
CNMax=dU/ Δ Umin (5)
Minimum control periodicity CNMin are as follows:
CNMin=dU/ Δ Umax (6)
In formula, Δ UminFor minimum voltage increment, determined by electric machine controller control resolution ratio；ΔUmaxFor maximum voltage increasing
Amount, is determined by motor responding ability；That is CNMax is using minimum voltage increment Delta UminWhen maximum control periodicity；CNMin
To use maximum voltage increment Delta UmaxWhen minimum control periodicity.
After step 4, control voltage gradient computing module receive target voltage increment and control periodicity, according to formula
(7) control voltage gradient is determined；Current control voltage is determined according to formula (8), is exported to power-supply controller of electric.
U(n)=U(n-1)+ΔU (8)
Wherein, U(n)To control voltage value, U(n-1)For current output voltage value, Δ U is that voltage adjusts gradient, dU target electricity
Incremental value is pressed, CycNum is control periodicity.
Later, power-supply controller of electric is according to the control voltage value U(n), electric power output voltage is controlled, to guarantee underground electricity consumption
The response speed and control stability of equipment (load motor).
During the work time, it when the electric current decrease speed of circuit for controlling motor is more than threshold value (0.5A/s) of setting, says
The load of bright downhole electrical motor reduces suddenly, it can be determined that is that the plug of bridge plug is pulled off, bridge plug is launched successfully, and equipment can be normal
Gug controls EP (end of program).
Bridge plug delivery tool is during underground work, since ground handling operator can not observe underground work progress, such as
Fruit launch do not complete when gug, it will cause charge bearing detecting cable to be pulled off, equipment can not gug, influence oil well exploitation make
Industry causes serious production accident.The present invention, as status feedback information, passes through the variation feelings of analysis electric current using circuital current
Condition, the working condition of accurate judgement underground equipment can effectively avoid the generation of accident.
The electric machine control system of oil field provided by the invention bridge plug delivery tool is supplied using programmable DC regulated power supply
Electricity, to realize the dynamic compensation of cable voltage drop.System for using D.C. regulated power supply to power for electrical equipment, works as power supply
Farther out with electrical equipment distance, when conductor resistance is larger, it will usually the output voltage of power supply is improved, for the circuit of compensating wire
Loss.The present invention uses programmable DC regulated power supply, and the pressure drop of conducting wire can be calculated by model, and dynamic adjusts the defeated of power supply
Voltage out solves the variation issue of line loss, improves electrical equipment control precision.
Before every secondary device is gone into the well, as soon as being operated by button K, computer can measure cable by the relationship of voltage and current
Resistance improve the accuracy of cable voltage drop compensating for loss and damage so as to modify the parameter in model of compensation control, guarantee motor
Always work in perfect condition.
The control gradient of electric power output voltage is automatically determined using ADAPTIVE CONTROL.It is big according to the deviation of output voltage
Small and feedback current change rate, the adaptive voltage for adjusting regulated power supply controls gradient, so that the operating voltage of load motor
Rapidly return back to rated value；Guarantee the response speed and control stability of electric equipment under ground (load motor).
Table 1 is to be pacified using the motor control method of the electronic bridge plug delivery tool in oil field provided by the invention in a bridge plug
Data record during dress.
Current and voltage data record sheet in 1 circuit of table
| Time s | Electric current | Supply voltage | Electric moter voltage |
| 0 | 0.0004 | 60 | 59.94 |
| 4 | 0.2622 | 100 | 60.67 |
| 8 | 0.2827 | 140 | 97.595 |
| 12 | 0.3721 | 225.8329 | 170.0179 |
| 16 | 0.373 | 225.9679 | 170.0179 |
| 20 | 0.3728 | 225.9379 | 170.0179 |
| 24 | 0.3793 | 226.9132 | 170.0182 |
| 28 | 0.3868 | 228.0386 | 170.0186 |
| 32 | 0.3986 | 229.8091 | 170.0191 |
| 36 | 0.4227 | 233.4253 | 170.0203 |
| 40 | 0.4569 | 238.5569 | 170.0219 |
| 44 | 0.4978 | 244.6939 | 170.0239 |
| 48 | 0.5603 | 254.0719 | 170.0269 |
| 52 | 0.6824 | 272.3928 | 170.0328 |
| 56 | 0.792 | 288.838 | 170.038 |
| 60 | 0.9146 | 307.2339 | 170.0439 |
| 64 | 1.0445 | 326.7251 | 170.0501 |
| 68 | 1.1791 | 346.9216 | 170.0566 |
| 72 | 1.3209 | 368.1984 | 170.0634 |
| 76 | 1.4642 | 389.7003 | 170.0703 |
| 79 | 0.2 | 0 | 0 |
As shown in figure 4, being the change curve of the voltage and current in the bridge plug installation process obtained according to data in table 1.
It can be seen from the figure that with the increase of motor workload, feedback current constantly increases, by controlling the regulation of computer, surely
The output voltage of voltage source regularly increases, so that the stable operating voltage of motor, in 170V, control effect is good.It is working
Process later period, electric current reduce suddenly, illustrate that the load of motor declines rapidly, and control logic judgement is that the plug of bridge plug is pulled off,
Installment work is completed, and the output voltage of regulated power supply is zeroed out, and launching work terminates.
Although the embodiments of the present invention have been disclosed as above, but its is not only in the description and the implementation listed
With it can be fully applied to various fields suitable for the present invention, for those skilled in the art, can be easily
Realize other modification, therefore without departing from the general concept defined in the claims and the equivalent scope, the present invention is simultaneously unlimited
In specific details and legend shown and described herein.
Claims (7)
1. a kind of oil field motor control method of electronic bridge plug delivery tool characterized by comprising
Step 1: measuring the resistance value of cable before going into the well, the voltage Controlling model of power supply is determined；
Step 2: the electric current in the course of work in real-time measurement circuit, and power supply is obtained according to the electric current and current changing rate
Voltage adjust gradient；
Step 3: control voltage is calculated, to control the output voltage of power supply；
U(n)=U(n-1)+ΔU；
In formula, U(n)To control voltage value, U(n-1)For current output voltage value, Δ U is that voltage adjusts gradient；
Wherein, during the work time, when the amplitude that the electric current in circuit reduces is more than threshold value, it is judged as that bridge plug is installed；
The threshold value is 0.5A/s.
2. the oil field according to claim 1 motor control method of electronic bridge plug delivery tool, which is characterized in that described
Voltage adjustment gradient calculation method include:
Step 1 determines target voltage values；
Step 2 calculates target voltage increment；
Step 3, calculating reach the control periodicity of the target voltage increment；
Step 4 calculates voltage adjustment gradient.
3. the oil field according to claim 2 motor control method of electronic bridge plug delivery tool, which is characterized in that in institute
It states in step 3, the control periodicity are as follows:
In formula, CNMax is maximum control periodicity；CNMin is minimum control periodicity；ΔIffFor filtered curent change
Rate；ΔImax、ΔIminRespectively maximum current increment and minimum current increment.
4. the oil field according to claim 3 motor control method of electronic bridge plug delivery tool, which is characterized in that in institute
It states in step 1, target voltage values are as follows:
Uobj=Uload_c+RIff；
Wherein, Uload_cFor Rated motor voltage；R is cable resistance, IffFor filtered current value.
5. the oil field according to claim 3 or 4 motor control method of electronic bridge plug delivery tool, which is characterized in that
In the step 2, target voltage increment are as follows:
DU=Uobj-U(n-1)；
In formula, UobjFor target voltage values, U(n-1)For current output voltage value.
6. the oil field according to claim 5 motor control method of electronic bridge plug delivery tool, which is characterized in that in institute
It states in step 4, the voltage adjusts gradient are as follows:
In formula, dU is target voltage increment, and CycNum is control periodicity.
7. the oil field according to claim 6 motor control method of electronic bridge plug delivery tool, which is characterized in that use
Single order low-pass digital filter inhibits interference signal, filtered current value are as follows:
In formula,Respectively (n-1)th and the filtered current value of n-th；For n-th sample rate current
Value；A is filter factor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810799787.0A CN108988711B (en) | 2018-07-20 | 2018-07-20 | A kind of motor control method of the electronic bridge plug delivery tool in oil field |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810799787.0A CN108988711B (en) | 2018-07-20 | 2018-07-20 | A kind of motor control method of the electronic bridge plug delivery tool in oil field |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108988711A CN108988711A (en) | 2018-12-11 |
| CN108988711B true CN108988711B (en) | 2019-11-29 |
Family
ID=64549589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810799787.0A Expired - Fee Related CN108988711B (en) | 2018-07-20 | 2018-07-20 | A kind of motor control method of the electronic bridge plug delivery tool in oil field |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108988711B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112202388B (en) * | 2020-09-27 | 2021-12-14 | 台安科技(无锡)有限公司 | Multistage series H bridge power unit protection device of high-voltage frequency converter |
| CN113252358B (en) * | 2021-05-12 | 2022-10-25 | 东风电子科技股份有限公司 | Vehicle window state detection method, system, device, processor and storage medium thereof based on current gradient direction change dynamics |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7586313B2 (en) * | 2007-04-26 | 2009-09-08 | Schlumberger Technology Corporation | Determining electrical characteristics of an electrical cable |
| WO2015184337A1 (en) * | 2014-05-30 | 2015-12-03 | Dialog Semiconductor Inc. | Adaptive cable drop compensation |
| CN106301019B (en) * | 2015-05-15 | 2019-04-02 | 福州瑞芯微电子股份有限公司 | Primary side feedback inverse-excitation type switch power-supply and its cable compensation method |
| CN105700607B (en) * | 2016-01-25 | 2018-02-06 | 昆山龙腾光电有限公司 | Supply voltage adjusts circuit and electronic installation |
| CN106160472A (en) * | 2016-08-11 | 2016-11-23 | 深圳欧创芯半导体有限公司 | Line loss compensation method and device for electric pressure converter |
| CN206698119U (en) * | 2017-02-20 | 2017-12-01 | 苏州智浦芯联电子科技股份有限公司 | A kind of Switching Power Supply output cable voltage-drop compensation circuit |
-
2018
- 2018-07-20 CN CN201810799787.0A patent/CN108988711B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN108988711A (en) | 2018-12-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108988711B (en) | A kind of motor control method of the electronic bridge plug delivery tool in oil field | |
| EP2549615B1 (en) | System and method for controlling voltage on a distribution feeder | |
| CN104052077B (en) | A kind of direct current transportation inverter side control method for frequency | |
| CN103986382B (en) | Method for determining under excitation limiting curve of hydro-generator based on dropwise impedance circle | |
| CN106558883B (en) | A kind of electric network fault control system for reactive power compensator | |
| CN106522916A (en) | Fuzzy-PID-control-based automatic drill feeding device and method | |
| CN101394147B (en) | DC motor speed control device and method | |
| CN203838304U (en) | Delivery inspection system for motor controllers | |
| CN108667082B (en) | Line loss compensation method, device and system | |
| CN101933211B (en) | Method for operating a wind turbine | |
| CN100483870C (en) | Automatic adjusting device and method of the variable capacitor of the RF board bar CO2 laser matching system | |
| CN104749504A (en) | Experiment method of dielectric response of frequency domain of traction transformer under loading condition | |
| CN108287292A (en) | The fast searching method of multicore cable trouble location | |
| CN105490344B (en) | Charging electric vehicle current control method and its control system | |
| CN104240036B (en) | A kind of Transient Voltage Stability quantitative estimation method based on critical system equiva lent impedance | |
| CN110137943A (en) | Stability of power system judgment method and device based on broad sense operation short-circuit ratio | |
| CN111999562B (en) | Method for measuring system impedance by using generator phase-in operation | |
| WO2015192273A1 (en) | Self-adaptive modeling apparatus for three-phase alternating-current electric arc furnace, and simulation algorithm therefor | |
| CN110289605B (en) | Intelligent direction protection method for hybrid compensation circuit based on instantaneous power curve cluster | |
| CN108445743A (en) | Coalcutter invariable power Fuzzy control system and method | |
| CN207037031U (en) | Switching equipment temperature rise experimental rig | |
| CN106684929A (en) | Direct current transmission control method based on wind-thermal direct-current island system | |
| CN106354022A (en) | Brushless direct current motor and control method and system thereof | |
| CN106787717A (en) | A kind of four line programmable power supply circuits | |
| CN108033673B (en) | Anti-interference method of optical fiber drawing tower |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20191129 Termination date: 20210720 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |